Transmissible spongiform encephalopathies (TSEs) cause spongy degeneration of the brain with severe and fatal neurological symptoms in humans and animal. TSEs include scrapie, which affects sheep and goats; bovine spongiform encephalopathy (BSE), which affects cattle; transmissible mink encephalopathy; feline spongiform encephalopathy; chronic wasting disease (CWD) of cervids including mule deer, white-tailed deer, black-tailed deer, and elk; and kuru, Creutzfeldt-Jakob disease, Gerstmann-Straussler syndrome, fatal familial insomnia, and variant Creutzfeldt-Jakob disease (vCJD), which affect humans.
The only identified component of the agent causing TSEs is PrPSc, an abnormal aggregating isoform of PrPc. Current methods of detecting PrPSc subject a sample to proteolysis with proteinase K to destroy PrPc. The presence of surviving PrPSc is then determined by an immunoassay using an antibody that is not selective for PrPSc in the presence of PrPc. See Serban et al., Neurology, 40:110 1990. This methodology excludes the use of an antibody for capture or detection during the proteolysis step. Proteinase K must be removed or deactivated before any antibodies can be introduced to the assay.
Methods are needed that can rapidly identify samples containing TSEs with minimal sample handling, discriminate between the normal and disease-associated conformer of Prp independent of proteinase K digestion, and that can be automated for high throughput applications.